Method setData

API/fleece/Mutable.hh:64–64

            template <class T>
        void operator= (const T &value)             {_coll.set(_key, value);}
        void setData(slice value)                   {_coll.set(_key).setData(value);}
        void remove()                               {_coll.remove(_key);}

        operator FLSlot()                           {return _coll.set(_key);}